I checked Their repository, and its last release was about 3 years ago, with only three 1/2 years old issues still open. And Wikipedia also confirms that.
Is this project still actively maintained or developed? Does anyone use it or recommend using it?
When looking at the repository, you should look at the commits, not releases. Not all open source projects have regular releases, but looking at calligra repository, it seems they have constant stream of commits from past three years. I would say it is still in active development.
Well, but I don’t see any nightly builds even. Or any repo package with latest build. Even Arch package version of Calligra is the latest 3 years old release.
So, the only way to use Calligra with the latest commit is to download the source and compile it yourself. And You know that it’s not going to be a happy compiling.
Well, there are two interpretations to your question.
Literal: is Calligra unmaintained? Clearly not.
Spirit of the question: Can non-developer get a more recent release than three years ago? Apparently not and the release part is clearly neglected somewhat.
open hub defines the development activity as “Very High Activity”.